cve/2021/CVE-2021-30639.md

CVE-2021-30639

Description

A vulnerability in Apache Tomcat allows an attacker to remotely trigger a denial of service. An error introduced as part of a change to improve error handling during non-blocking I/O meant that the error flag associated with the Request object was not reset between requests. This meant that once a non-blocking I/O error occurred, all future requests handled by that request object would fail. Users were able to trigger non-blocking I/O errors, e.g. by dropping a connection, thereby creating the possibility of triggering a DoS. Applications that do not use non-blocking I/O are not exposed to this vulnerability. This issue affects Apache Tomcat 10.0.3 to 10.0.4; 9.0.44; 8.5.64.

POC

Reference

• https://kc.mcafee.com/corporate/index?page=content&id=SB10366
• https://www.oracle.com/security-alerts/cpujan2022.html

Github

• https://github.com/20142995/nuclei-templates
• https://github.com/cyb3r-w0lf/nuclei-template-collection